public class SubstringFunction extends Object implements Function
4.2
string substring(string,number,number?)
The substring function returns the substring of the first argument starting at the position specified in the second argument with length specified in the third argument. For example,
substring("12345",2,3)
returns"234"
. If the third argument is not specified, it returns the substring starting at the position specified in the second argument and continuing to the end of the string. For example,substring("12345",2)
returns"2345"
.More precisely, each character in the string (see [3.6 Strings]) is considered to have a numeric position: the position of the first character is 1, the position of the second character is 2 and so on.
NOTE: This differs from Java and ECMAScript, in which theString.substring
method treats the position of the first character as 0.The returned substring contains those characters for which the position of the character is greater than or equal to the rounded value of the second argument and, if the third argument is specified, less than the sum of the rounded value of the second argument and the rounded value of the third argument; the comparisons and addition used for the above follow the standard IEEE 754 rules; rounding is done as if by a call to the round function. The following examples illustrate various unusual cases:
substring("12345", 1.5, 2.6)
returns"234"
substring("12345", 0, 3)
returns"12"
substring("12345", 0 div 0, 3)
returns""
.
substring("12345", 1, 0 div 0)
returns""
substring("12345", -42, 1 div 0)
returns"12345"
substring("12345", -1 div 0, 1 div 0)
returns""
Constructor and Description |
---|
SubstringFunction()
Create a new
SubstringFunction object. |
Modifier and Type | Method and Description |
---|---|
Object |
call(Context context,
List args)
Returns a substring of an XPath string-value by character index.
|
public SubstringFunction()
SubstringFunction
object.public Object call(Context context, List args) throws FunctionCallException
call
in interface Function
context
- the context at the point in the
expression when the function is calledargs
- a list that contains two or three itemsString
containing the specifed character subsequence of
the original string or the string-value of the context nodeFunctionCallException
- if args
has more than three
or less than two itemsCopyright 2001–2022 The Jaxen Project. All rights reserved.